Tested on Arch Linux.
Linux 6.3.4-arch2-1
coreutils 9.3-1

Also tested on Fedora 38 - no errors:
Linux 6.2.14-300
coreutils 9.1-12

User work: backup to usb key with sync

usb key inserted 
$ e2fsck /dev/sdb1
e2fsck 1.47.0 (5-Feb-2023)
backup: clean, 19489/327680 files, 769044/1280000 blocks

usb key mounted on /media
# lsblk -f
...
sdb                                                                            
└─sdb1 ext4   1.0   backup 4e29cf48-xxxxxxxxxxxxxxx    1.7G    59% /media

Backup operation:
$ du -h charts/
< around 30 files and dirs of single depth >
128M	charts/
# rm -r /media/dir1/dir2/charts/
# cp -pr charts /media/dir1/dir2/
# sync
< waiting>

System status during sync:
$ top -p 5627 
Tasks:   1 total,   0 running,   1 sleeping,   0 stopped,   0 zombie
%Cpu0  :  0.3 us,  0.0 sy,  0.0 ni, 53.2 id, 45.8 wa,  0.0 hi,  0.7 si,  0.0 st
%Cpu1  :  0.3 us,  0.7 sy,  0.0 ni,  0.0 id, 99.0 wa,  0.0 hi,  0.0 si,  0.0 st
MiB Mem :   1963.1 total,    146.1 free,    762.1 used,   1054.9 buff/cache
MiB Swap:   8000.0 total,   7957.2 free,     42.8 used.    941.4 avail Mem 

    PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND                                                                               
   5627 root      20   0    5496   1664   1664 D   0.0   0.1   0:00.00 sync                                                                                  

$ journalctl
...
< kernel dumps >
May 30 14:53:42 r61i kernel: INFO: task sync:5333 blocked for more than 122 seconds.
May 30 14:53:42 r61i kernel:       Tainted: G     U             6.3.4-arch2-1 #1
May 30 14:53:42 r61i kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
May 30 14:53:42 r61i kernel: task:sync            state:D stack:0     pid:5333  ppid:4839   flags:0x00000002
May 30 14:53:42 r61i kernel: Call Trace:
...
May 30 16:40:12 r61i kernel: Future hung task reports are suppressed, see sysctl kernel.hung_task_warnings
$

It took around 5-10 min to finish sync.

$ umount /media
$ e2fsck /dev/sdb1
e2fsck 1.47.0 (5-Feb-2023)
backup: clean, ...
$